1. Field of the Invention
The present invention relates to a communication device and communication control technology in the communication device.
2. Description of the Related Art
As the related art of a field of the present technology, JP-2010-220066-A is known. In JP-2010-220066-A, “a wrong PC detecting unit 204 of a monitoring unit 101 refers to a registration completion list and a detection list, detects an ARP request packet transmitted from a wrong node, and stores information needed to exclude an access by the wrong node in a transmission list. An ARP table camouflage unit 206 camouflages a MAC address of the wrong node with a MAC address of the monitoring unit 101, in an ARP table. A camouflage ARP request transmitting unit 207 transmits a camouflage ARP request packet to a node of the access destination of the wrong node. After an ARP reply packet for the camouflage ARP request packet is received from the node of the access destination of the wrong node, a camouflage ARP reply transmitting unit 208 transmits a camouflage ARP reply packet to the wrong node” is described (refer to Abstract).
In the related art, in a network (hereinafter, referred to as the “closed network”) system used in a closed space to be represented by a company network, which is not physically connected to an external network and is used relatively safely against an attack from the external network by applying multiplex firewalls, when a wrong terminal is connected to the closed network, communication of an authentication terminal is protected by authentication terminal technology of JP-2010-220066-A using an address resolution protocol (ARP) (“ARP Cache Poisoning” Steve Gibson (2005-12-11)) to be one of address resolution packets and media access control (MAC) authentication. In the authentication terminal technology, the MAC address that is one of network addresses and is a physical address (a hardware address) is used as authentication information and communication of the terminal is permitted or prohibited by managing the MAC address of the terminal that exists in the closed network.